Thanks. Didn't get to that. Perhaps that message should come first before the steps? Well, thanks. @stevieb So any other means to control the onboard LED lights?
– RexfordJul 19 '17 at 14:22

1

@Rexford I honestly don't know if there's another way. I've never needed that functionality. You could email the maintainers of that site and request they put the notice at the top of the page as opposed to the bottom...
– steviebJul 19 '17 at 14:25

Sorry, this does not hold since 2016, as the LEDs are accessible to the best of my knowledge, see my answer below.
– TheDiveOJul 20 '17 at 9:31

This answer worked for me on Raspberry Pi 3B running Raspbian Lite Stretch to blink the green activity light. (I did not attempt to control the red power light.) It involves an obscure command to write to the mailbox interface for the light.

The following Python code seems to work well for me to control the onboard LEDs on a Pi 3B running Raspbian GNU/Linux 9 (stretch). Save it to led.py, then you can call it from your main program with import led then led.control("red", "flash"), for example.

If you don't want to use Python, you can issue the commands directly in a shell. For example, to turn the red LED off, echo 0 | sudo tee /sys/class/leds/led1/brightness should do the trick.

While it is correct that the onboard LEDs are on an expander, they are already accessible for quite some time. See this github issue 1363 from 2016. According to its documentation, the pi3-act-led overlay "changes the GPIO controller back to the standard one and restores the dtparams".

So how would I turn it on and off? I'm sorry, but the link didn't provide any easy to understand way to do the on or off.
– RexfordJul 21 '17 at 9:39

After you have configured the boot to load the overlay, the existing tutorials on how to control the LEDs should apply again.
– TheDiveOJul 21 '17 at 10:38

@TheDiveO I've attempted to add dtoverlay=pi3-act-led,gpio=18 as in the linked answer, but then I still could not control the activity LED. I also tried gpio=47. I also cannot find any reference to anyone who has gotten this to work.
– rgovMar 28 '18 at 4:57